PCI bandwidth

execcr · Post by **execcr** » Wed Dec 09, 2009 8:48 pm

Hi, i'll still tring to resolve a problem with my pci dvr 8 channel card. Sometimes i get I/O error like the input is unplegged.

I run 2 cameras at 640x480 in 24bit rgb. At 10fps each zmc crash randomly. A 6 fps is stable. So i think to a some kind of memory issue (not reletad to sysctl parameters like shmmax and shmall after the thousand of attemps i've done)
So i started to search to another problem location.... and i have tought to the pci bus.
So, with some calc it result a 122mb consuption of ram from the cams. And with only 2 card! What happen if i attach another cam? The pci bus 33mhz doesnt have only 133MB/sec of bandwidth??

mastertheknife · Post by **mastertheknife** » Thu Dec 17, 2009 2:45 am

You aren't even close to saturate the PCI bus.
640x480 24bit at 10fps is a 8.78 MB/s stream when uncompressed.
So for two cameras its around 16-17 MB/s, not even close to the 133 MB/s limit for PCI.
Is the card inserted all the way in? also, might want to try cleaning the PCI slot and the PCI pins of the card.

kingofkya · Post by **kingofkya** » Thu Dec 17, 2009 5:55 am

also check air flow most computers that have random errors like this simply need to be cleaned out also try getting the heat syncs for the capture card or reduce frame rate.

Unless its a ECS board the longest i have had one of thous running is a year and a half.

execcr · Post by **execcr** » Fri Dec 18, 2009 7:53 pm

thanks to the explanation. I was completely out of way.

My PVR card have yet passive heatsink. I will try to place a fan directly on it.

thanks!